1. Field of the Invention.
The present invention relates to polygonal cartons and more specifically to a polygonal carton made from a unitary blank of stiff but foldable material and having a strong weight supporting bottom. Although the carton of the present invention can have any number of sides, i.e., three or more, the preferred embodiments of the invention have an even number of sides and in particular six or more sides, i.e., cartons approaching a cylindrical, drum or bushel-basket shape. Polygonal cartons of this type are presently classified in class 229 subclasses 37, 39, 41 and related subclasses.
2. Description of the Prior Art.
Heretofore various polygonal cartons made from a unitary paperboard blank have been proposed. Examples of such previously proposed polygonal cartons are disclosed in the following patents.
U.S. Pat. Nos.
1,909,649 PA2 2,000,210 PA2 2,517,552 PA2 2,761,611 PA2 3,071,308 PA2 3,559,871 PA2 3,526,352 PA2 3,700,161 PA2 3,768,720
Typically these cartons are made of paperboard which has only a limited weight supporting capacity. As a result there is a limit on the weight supporting capacity of these cartons and heretofore polygonal cartons with six or more sides have not been widely used in place of drums or cylindrical containers currently in use for storing fluid materials having significant weight.
Some attempts have been made, however, to improve the construction and strength of end closures for polygonal cartons and U.S. Pat. Nos. 3,526,352 and 3,700,161 referred to above disclose several improved end closures.
As will be described in detail hereinafter the polygonal carton of the present invention provides a further improvement, namely, a polygonal carton having a bottom construction which has significant weight supporting capacity.